This disclosure relates to a gas turbine engine mid turbine frame bearing support.
One typical gas turbine engine includes multiple, nested coaxial spools. A low pressure turbine is mounted on a first spool, and a high pressure turbine is mounted on a second spool. A mid turbine frame, which is part of the engine's static structure, is arranged axially between the low and high pressure turbines. The turbine frame includes an inner hub and outer shroud with a circumferential array of airfoils adjoining the hub and shroud, providing a gas flow path.
One typical static structure design includes a hot airfoil structure that is cooled by air channeled in a cooling cavity. The hot airfoil creates one side of this cavity, while the cold frame, or support, provides the other. The cold frame is also coupled to the bearing compartment, which must be kept cool to prevent the oil from overheating. The cooling cavity is sealed. Any leakage from the cooling cavity is heated by convection against the hot airfoil, causing the leakage to drive a thermal gradient across the seal carrier and cold frame.